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We explored how changes of viral abundance and community composition among four contrasting regions in the Southern Ocean relied on physicochemical and microbiological traits. During January–February 2015, we visited areas north and south of the South Orkney Islands (NSO and SSO) characterized by low temperature and salinity and high inorganic nutrient concentration, north of South Georgia Island (NSG) and west of Anvers Island (WA), which have relatively higher temperatures and lower inorganic nutrient concentrations. Surface viral abundance (VA) was highest in NSG (21.50 ± 10.70 × 106 viruses mL−1) and lowest in SSO (2.96 ± 1.48 × 106 viruses mL−1). VA was positively correlated with temperature, prokaryote abundance and prokaryotic heterotrophic production, chlorophyll a, diatoms, haptophytes, fluorescent organic matter, and isoprene concentration, and was negatively correlated with inorganic nutrients (NO3−, SiO42−, PO43−), and dimethyl sulfide (DMS) concentrations. Viral communities determined by randomly amplified polymorphic DNA–polymerase chain reaction (RAPD-PCR) were grouped according to the sampling location, being more similar within them than among regions. The first two axes of a canonical correspondence analysis, including physicochemical (temperature, salinity, inorganic nutrients—NO3−, SiO42−, and dimethyl sulfoniopropionate -DMSP- and isoprene concentrations) and microbiological (chlorophyll a, haptophytes and diatom, and prokaryote abundance and prokaryotic heterotrophic production) factors accounted for 62.9% of the variance. The first axis, temperature-related, accounted for 33.8%; the second one, salinity-related, accounted for 29.1%. Thus, different environmental situations likely select different hosts for viruses, leading to distinct viral communities.

A range of volatile organic compounds (VOCs) have been found to be released during zooplankton grazing on microalgae cultivated for commercial purposes. However, production of grazing-derived VOCs from environmentally relevant species and their potential contribution to oceanic emissions to the atmosphere remains largely unexplored. Here, we aimed to qualitatively explore the suite of VOCs produced due to grazing using laboratory cultures of the marine microalga Isochrysis galbana and the herbivorous heterotrophic dinoflagellate Oxyrrhis marina with and without antibiotic treatment. The VOCs were measured using a Vocus proton-transfer-reaction time-of-flight mass spectrometer, coupled to a segmented flow coil equilibrator. We found alternative increases of dimethyl sulfide by up to 0.2 nmol dm−3 and methanethiol by up to 10 pmol dm−3 depending on the presence or absence of bacteria regulated by antibiotic treatment. Additionally, toluene and xylene increased by about 30 pmol dm−3 and 10 pmol dm−3, respectively during grazing only, supporting a biological source for these compounds. Overall, our results highlight that VOCs beyond dimethyl sulfide are released due to grazing, and prompt further quantification of this source in budgets and process-based understanding of VOC cycling in the surface ocean.

Alkylamines, volatile organic nitrogen compounds with low molecular weight, are present in the surface ocean and participate in the marine biogeochemical nitrogen cycle, atmospheric chemistry and cloud formation. Alkylamines have been detected in polar regions, suggesting that these areas constitute emission hotspots of these compounds. However, knowledge of the sea surface distribution patterns and factors modulating alkylamines remain limited due to their high reactivity and low concentrations, which hamper accurate measurements. We investigated the presence and distribution of alkylamines in seawaters around the Antarctic Peninsula and the northern Weddell Sea during the late austral summer and explored their potential links to marine microbiota. Alkylamines were ubiquitous in all analysed samples, accounting for ∼ 2 % of the dissolved and particulate organic nitrogen pool. The only particulate form found was trimethylamine (TMA), detected for the first time in Antarctic waters at concentrations of 9.7 ± 4.6 nM. We efficiently measured dissolved trimethylamine (TMA, 20.9 ± 15.2 nM), dimethylamine (DMA, 32.3 ± 32.7 nM) and diethylamine (DEA, 7.2 ± 1.7 nM) across the surveyed area, while dissolved monomethylamine (MMA, 12.7 ± 0.1 nM) remained below the detection limit in most samples. Variations in alkylamine concentrations did not align with the overall phytoplankton biomass but with specific biological components. TMA was predominantly associated with, and released from, nanophytoplankton. DMA was likely produced by the degradation of TMA or trimethylamine oxide by nanophytoplankton cells or associated heterotrophic bacteria. The sources of DEA remain unclear but were suggestive of a distinct biogeochemical pathway from those of TMA and DMA. MMA is thought to primarily originate from bacterial degradation of nitrogen-based osmolytes or amino acids, but detection in too few samples precluded any robust association with microbiota. This study reveals that volatile alkylamines are widespread in Antarctic surface waters, where they are primarily sourced from nanophytoplankton cells and associated heterotrophic bacteria and protists.

Marine viruses are key components of marine microbial communities, as they influence the cellular abundances and the community structure of microbes, participate in their genetic exchange, and intervene in the ocean biogeochemical cycles. Most studies dealing with the role of viruses in the marine environment have been done from a bulk community point of view, but going from the bulk community perspective to specific virus-host relationships is essential in order to understand the role of viruses in shaping a determined host community, in modifying host genomes, and ultimately in the release of organic compounds from the lysed cells. For this reason, in this thesis we implemented and applied different methodologies that are able to detect, visualize and quantify virus-host interactions in marine eukaryotes at the single cell level. We focused on picoeukaryotes (cells <3 µm) because they play crucial roles in marine food webs and biogeochemical cycles, and virus-host interactions in natural populations of these minute eukaryotes are largely unknown. In the first chapter we combined previously developed techniques, used to assess prokaryotic host-phage interactions, to implement VirusFISH for detecting specific virus-host dynamics, using as a model system the photosynthetic picoeukaryote Ostreoccocus tauri and its virus OtV5. With the VirusFISH technique, we could also monitor the infection, as well as quantify the free viruses produced during the lysis of the host in a non-axenic culture, which allowed the calculation of the burst size. This study set the ground for the application of the VirusFISH technique to natural samples.In the second chapter of this thesis, we applied VirusFISH to seawater samples from the Bay of Biscay (Cantabrian Sea) to study the dynamics of viral infection in natural populations of Ostreococcus along a seasonal cycle. We were able to quantify the percentage of cells infected over time, and compared these results with the transcriptional viral and host activities derived from metatranscriptomic data. This constitutes the first study where a specific viral-host interaction has been visualized and monitored over time in a natural system. Picoeukaryotes in the ocean are prevalently uncultured, and thus, in the third chapter of this thesis we went an step further to unveil novel viral-host relationships in eukaryotic uncultured hosts. For this purpose, we mined single amplified genomes (SAGs) of picoeukaryotes obtained during the Tara Oceans expedition for viral signatures. We found that almost 60% of the cells analyzed presented an associated virus with narrow host specificity. Some of the viral sequences were widely distributed and some geographically constrained, and they were preferentially found at the deep chlorophyll maximum. Moreover, we found a mavirus virophage potentially integrated in four SAGs of two different lineages, suggesting the presence of virophages is more common than previously thought.In summary, in this thesis we have implemented and used techniques that allow us to detect and monitor specific virus-host interactions, which is one of the major challenges in marine viral ecology. On the one hand, VirusFISH arises as a powerful technique that can be easily adapted to any host-virus system that has been genome-sequenced. On the other hand, the results obtained with the single cell genomics offer the opportunity to formulate hypothesis based on detected viral-host interactions in uncultured prevalent marine picoeukaryotes, which can be later tested using experimental approaches.

One of the major challenges in viral ecology is to assess the impact of viruses in controlling the abundance of specific hosts in the environment. For this, techniques that enable the detection and quantification of virus-host interactions at the single-cell level are essential. With this goal in mind, we implemented VirusFISH (Virus Fluorescence in situ Hybridization) using as a model the marine picoeukaryote Ostreococcus tauri and its virus OtV5. VirusFISH allowed the visualization and quantification of the fraction of infected cells during an infection experiment. We were also able to quantify the abundance of free viruses released during cell lysis and assess the burst size of our non-axenic culture, because we could discriminate OtV5 from phages. Our results showed that although the major lysis of the culture occurred between 24 and 48 h after OtV5 inoculation, some new viruses were produced between 8 and 24 h, propagating the infection. Nevertheless, the production of viral particles increased drastically after 24 h. The burst size for the O. tauri-OtV5 system was 7±0.4 OtV5 per cell, which was consistent with the estimated amount of viruses inside the cell prior to cell lysis. With this work we demonstrate that VirusFISH is a promising technique to study specific virus-host interactions in non-axenic cultures, and set the ground for its application in complex natural communities.

Purpose Our study aims to determine whether there are differences in the degree of detection of prostate cancer (PCa) and CsPCa between fusion prostate biopsy (FPB), cognitive biopsy (PCB), and randomized, systematic biopsy (SB). Methods A retrospective analysis was carried out of 195 patients with suspected PCa at the San Cecilio University Clinical Hospital in Granada who underwent a prostate biopsy between January and December 2021. Patients were divided into three groups: group 1, patients undergoing FPB transperineally with ultrasound BK 3000 ( N  = 87); group 2, PCB ( N  = 59) transperineally; and group 3, transrectal SB ( N  = 49), the latter two, with an ultrasound BK Specto. Results We found differences in favor of image-directed biopsies (FPB and PCB) with a percentage of positive biopsies of 52.8% and 50%, respectively, compared to 41.4% with SB, but without these differences being significant. Given the controversy in performing prostate biopsies in PI-RADS 3 lesions reported in the literature, a subanalysis was performed excluding the FPB performed for PI-RADS 3 lesions (PI-RADS 4 and 5 are included), finding significant differences when comparing FPB with PCB and SB (group 1, 64% vs group 2, 45.8%; p  = 0.05) (group 1, 64% vs group 3, 42.9%; p  = 0.035). Conclusion With the results obtained in our series, we conclude that the finding of a PI-RADS 3 lesion in mpMRI should not be an absolute criterion to indicate prostate biopsy. On the other hand, for PI-RADS 4 and 5 lesions, FPB is recommended, which in this case turns out to be superior to PCB and SB.

Our objective was to improve the results of extracorporeal shock waves lithotripsy using hydroxycitric acid (HCA) like adjuvant therapy. Double blind randomized clinical trial using hydroxycitric acid versus placebo (ID NCT05525130). Multicenter study of adjuvant exposure to a food supplement with hydroxycitric acid (HCA), vs. placebo in patients with calcium oxalate and calcium phosphate lithiasis with indication for extracorporeal shock wave lithotripsy (ESWL). 81 patients were included in the study to compare the effect of HCA versus placebo. Stone fragmentation, the main efficacy variable. Other variables analyzed were stone size, Hounsfield Unit Stone and tolerability. Statistical study with SPSS, statistical significance p ≤ 0.05. Eighty-one patients were included, 40 in the intervention group with HCA and 41 in the control group with placebo. The average stone area was 174,36 mm2 (SD: 32,83 mm2) and the average hardness was 1128,11 (SD: 257,65), with no statistically significant differences between groups. Significant statistical differences were obtained in the analysis of the population by intention to treat and by protocol of the main variable, no fragmentation vs. fragmentation where 100% of the patients, who were given ESWL and took HCA, presented fragmentation while 17% of the patients with placebo did not reach fragmentation (p = 0.03). The adjuvant use of HCA in patients for whom ESWL has been indicated, facilitates stone fragmentation in all cases, which is not achieved in up to 17% of the patients who did not use HCA. We recommend the use of HCA in patients prior to shock wave treatment to improve their fragmentation in calcium stones.

BackgroundThe incidence of all periprosthetic fractures (PPF), which require complex surgical treatment associated with high morbidity and mortality, is predicted to increase. The evolving surgical management has created a knowledge gap regarding its impact on immediate outcomes. This study aimed to describe current management strategies for PPF and their repercussions for in-hospital outcomes as well as to evaluate their implications for the community.MethodsPIPPAS (Peri-Implant PeriProsthetic Survival Analysis) was a prospective multicentre observational study of 1387 PPF performed during 2021. Descriptive statistics summarized the epidemiology, fracture characteristics, management, and immediate outcomes. A mixed-effects logistic regression model was employed to evaluate potential predictors of in-hospital mortality, complications, discharge status, and weight-bearing restrictions.ResultsThe study encompassed 32 (2.3%) shoulder, 4 (0.3%) elbow, 751 (54.1%) hip, 590 (42.5%) knee, and 10 (0.7%) ankle PPF. Patients were older (median 84 years, IQR 77–89), frail [median clinical frailty scale (CFS) 5, IQR 3–6], presented at least one comorbidity [median Charlson comorbidity index (CCI) 5, IQR 4–7], were community dwelling (81.8%), and had outdoor ambulation ability (65.6%). Femoral knee PPF were most frequently associated with uncemented femoral components, while femoral hip PPF occurred equally in cemented and uncemented stems. Patients were managed surgically (82%), with co-management (73.9%), through open approaches (85.9%) after almost 4 days (IQR, 51.9–153.6 h), with prosthesis revision performed in 33.8% of femoral hip PPF and 6.5% of femoral knee PPF. For half of the patients, the discharge instructions mandated weight-bearing restrictions. In-hospital mortality rates were 5.2% for all PPF and 6.2% for femoral hip PPF. Frailty, age > 84 years, mild cognitive impairment, CFS > 3, CCI > 3, and non-geriatric involvement were candidate predictors for in-hospital mortality, medical complications, and discharge to a nursing care facility. Management involving revision arthroplasty by experienced surgeons favoured full weight-bearing, while an open surgical approach favoured weight-bearing restrictions.ConclusionsCurrent arthroplasty fixation check and revision rates deviate from established guidelines, yet full weight-bearing is favoured. A surgical delay of over 100 h and a lack of geriatric co-management were related to in-hospital mortality and medical complications. This study recommends judicious hypoaggressive approaches. Addressing complications and individualizing the surgical strategy can lead to enhanced functional outcomes, alleviating the economic and social burdens upon hospital discharge.Level of Evidence Level IV case series.Trial registration: registered at ClinicalTrials.gov (NCT04663893), protocol ID: PI 20-2041.

IntroductionThe EULAR points to consider (PtC) for reducing non-adherence need implementation.ObjectivesTo design, implement and evaluate a strategy based on the PtC to improve treatment adherence in rheumatoid arthritis (RA).MethodsA multidisciplinary panel cocreated an intervention that was subsequently tested in a cluster trial, where centres were randomised to access the developed intervention or follow the standard of care (SOC). 6-month initiation and implementation adherence were measured in consecutive patients with <2 years of RA. The results were discussed among the centres assigned to the intervention to explore barriers and facilitators to implementation.ResultsThe intervention was a two-sided website. The items on the patient site mainly addressed disease and treatment education, self-management and peer support. The healthcare professional site has tutorials on communication to improve trust and adherence, plus shared decision-making aids. It was tested in 141 RA patients (67 control and 74 intervention). Both groups increased adherence at 6 months, mainly in the control group (48% to 67% vs 42% to 47% in the intervention group). Implementation had been very low in relation to barriers identified as lack of time, inadequate focus (exclusively for nurses) and consideration of the current SOC as adequate.ConclusionDespite designing an intervention based on the best evidence, the results were inconclusive; the lack of a detected effect could be explained by the limited implementation, which was insufficient for the complexity of the changes required (change of culture).Trial register numberClinicalTrials.gov ID NCT05425485.

The identification of Parkinson’s disease (PD) biomarkers has become a main goal for the diagnosis of this neurodegenerative disorder. PD has not only been intrinsically related to neurological problems, but also to a series of alterations in peripheral metabolism. The purpose of this study was to identify metabolic changes in the liver in mouse models of PD with the scope of finding new peripheral biomarkers for PD diagnosis. To achieve this goal, we used mass spectrometry technology to determine the complete metabolomic profile of liver and striatal tissue samples from WT mice, 6-hydroxydopamine-treated mice (idiopathic model) and mice affected by the G2019S-LRRK2 mutation in LRRK2/PARK8 gene (genetic model). This analysis revealed that the metabolism of carbohydrates, nucleotides and nucleosides was similarly altered in the liver from the two PD mouse models. However, long-chain fatty acids, phosphatidylcholine and other related lipid metabolites were only altered in hepatocytes from G2019S-LRRK2 mice. In summary, these results reveal specific differences, mainly in lipid metabolism, between idiopathic and genetic PD models in peripheral tissues and open up new possibilities to better understand the etiology of this neurological disorder.